Rhein

Rhein (RH), an anthraquinone compound extracted from the Chinese herb rhubarb, exerts antitumour effects on various cancers. However, the role and underlying molecular mechanisms of RH in osteosarcoma remain unknown. In this study, we observed that RH significantly inhibited osteosarcoma cell proliferation, migration, invasion and stemness in vitro while promoting death and curtailing tumourigenesis in vivo. Mechanistically, RH downregulated the expression of FABP4 in osteosarcoma cells. The induction of death by RH was augmented by FABP4 knockdown and diminished by FABP4 overexpression. Depletion of FABP4 suppressed osteosarcoma cell proliferation in vitro and in vivo. Then, we found that TCF7L2 was directly bound to the FABP4 promoter and facilitated its transcription. Downregulation of TCF7L2 inhibited FABP4 expression and enhanced the anticancer effects of RH in osteosarcoma. Additionally, our investigations revealed that RH significantly upregulated miR-328-3p expression, resulting in the downregulation of TCF7L2 protein levels in osteosarcoma cells. Our findings indicate that miR-328-3p/TCF7L2/FABP4 axis is vital for the anticancer effects of RH and may be a potential therapeutic agent for osteosarcoma treatment.

This study presented the development of a novel adsorbent system through the synthesis of cationic surfactant-modified Cu-doped ZIF-8 (Cu@ZIF-8), leveraging the synergistic advantages of bimetallic-enhanced surface area and surfactant-mediated stability. Among various surfactants evaluated, dodecyltrimethylammonium bromide (DTAB)-functionalized Cu@ZIF-8 exhibited superior adsorption performance toward emodin and rhein, driven by combined π-π interactions and hydrogen bonding. This optimized adsorbent facilitated the development of an innovative analytical method integrating Cu@ZIF-8-based extraction with UPLC-UV for the trace-level quantification of target analytes in complex biological matrices. Comprehensive optimization of critical extraction and desorption parameters yielded a robust analytical protocol with excellent linearity (0.05-5.00 μg/mL; R² = 0.9993 and 0.9980), sensitive detection limits (0.01 μg/mL), and satisfactory recovery (92.73-108.86 %). The validated method successfully characterized the urinary pharmacokinetic profiles of emodin and rhein following rhubarb extract administration in rats. Compared to conventional protein precipitation approaches, this approach offers significant advantages in simplicity, analysis speed and environmental compatibility. These findings position surfactant-engineered Cu@ZIF-8 as a promising platform for bioanalytical applications, particularly in the quantification of anthraquinone derivatives in biological specimens.